Passive countermeasure methods

ABSTRACT

A method of performing passive countermeasures for an automotive vehicle ( 12 ) having a vehicle sensor complex ( 18 ) generating a vehicle sensor complex signal is provided. The method of performing passive countermeasures includes performing an accelerometer initiated passive countermeasure method and performing a sensor fusion initiated passive countermeasure method. An object is detected with a sensor fusion ( 14 ) and an object parameter signal is generated. The object parameter signal is compared with an object parameter threshold level. The sensor fusion initiated passive countermeasure method is terminated when the object parameter signal is greater than the object parameter threshold level.

BACKGROUND OF INVENTION

The present invention is related to U.S. patent application Ser. No.09/683,676 entitled “Collision Warning and Safety Countermeasure System”filed simultaneously herewith and incorporated by reference herein.

The present invention relates generally to collision warning systems,and more particularly to a method and apparatus for performing passivecountermeasures as to prevent an injury to an operator during acollision.

Collision warning and countermeasure systems are becoming more widelyused. Collision warning systems provide a vehicle operator knowledge andawareness of objects or vehicles within a close proximity so as toprevent colliding with those objects. Countermeasure systems exist invarious passive and active forms. Some countermeasure systems are usedto aid in prevention of a collision others are used to aid in theprevention of injury to a vehicle operator.

Collision warning systems and countermeasure systems currently exist invarious forms. Certain collision warning systems and countermeasuresystems are able to sense a vehicle or object in the close proximity toa host vehicle and warn the host vehicle operator, such that theoperator can take precautionary steps to prevent a collision or injury.Other collision warning systems and countermeasure systems activatepassive or active countermeasures such as air bags, load limiting seatbelts, or brake control whereby the system itself aids in preventing acollision or injury.

Currently collision warning systems and countermeasure systems are usedindependently and do not interact with each other in a cooperativefashion as to, in a combined fashion, further decrease the probabilityof a collision or injury. The current collision warning systems also donot utilize a majority of existing vehicle sensors such as tire pressuresensors and occupant classification sensors, in conjunction with thecollision warning systems and countermeasure systems again to furtherdecrease the probability of a collision or injury.

Separate from collision warning systems and countermeasure systems othersystems exist for autonomously controlling a vehicle. These systems mayinclude devices such as cameras, sensors, steering control, brakecontrol, and accelerator control. Autonomous type systems have primarilybeen used for military applications and not for collision and injuryprevention in automotive vehicles.

Current collision warning systems and countermeasure systems alsoperform passive countermeasures in response to accelerometer data. Theaccelerometer data is primarily received from accelerometers locatednear the outer surface of the vehicle. For example, an accelerometerlocated on a vehicle bumper or in a close proximity to that location istypically used to signal an airbag to deploy during a collision. Use ofthese externally located accelerometers to deploy passivecountermeasures is limiting in the prevention of injury during acollision in that they are limited in information of vehicle status andoperator status. In other words, the externally placed accelerometers donot supply information such as seat positioning, occupant positioning,or other related information that may be used to better prevent injury.

An ongoing concern for safety engineers is to provide a safer automotivevehicle with increased collision warning and safety countermeasureintelligence as to decrease the probability of a collision or an injury.Therefore, it would be desirable to provide an improved collisionwarning and safety countermeasure system for an automotive vehicle thatincorporates existing techniques and others to create a more efficientcollision and injury prevention system for an automotive vehicle.

SUMMARY OF INVENTION

The foregoing and other advantages are provided by a method ofperforming passive countermeasures for an automotive vehicle. A methodof performing passive countermeasures for an automotive vehicle having avehicle sensor complex generating a vehicle sensor complex signal isprovided. The method of performing passive countermeasures includesperforming an accelerometer initiated passive countermeasure method andperforming a sensor fusion initiated passive countermeasure method. Anobject is detected with a sensor fusion and an object parameter signalis generated. The object parameter signal is compared with an objectparameter threshold level. The sensor fusion initiated passivecountermeasure method is terminated when the object parameter signal isgreater than the object parameter threshold level.

One of several advantages of the present invention is that it provides amethod for deploying passive countermeasures in a cooperative manner asto efficiently prevent injury to a vehicle occupant.

Another advantage of the present invention is that it provides increasedvehicle intelligence as in assessing a potential collision situation anddetermining what actions to perform, when to perform the actions, and inwhat manner to perform the actions.

Additionally, the present invention provides vehicle and occupantrelated information in combination with accelerometer data to deploypassive countermeasures in a more comprehension manner.

Furthermore, the present invention provides a method for determiningwhether to deploy passive countermeasures at an earlier time in apotential collision event using pre-collision vehicle, occupant, andobject related information. The ability to assess pre-collisioninformation allows the present invention to provide an increased safetyperformance method for deploying passive countermeasures overtraditional accelerometer based collision warning systems andcountermeasure systems.

The present invention itself, together with attendant advantages, willbe best understood by reference to the following detailed description,taken in conjunction with the accompanying figures.

BRIEF DESCRIPTION OF DRAWINGS

For a more complete understanding of this invention reference should nowbe had to the embodiments illustrated in greater detail in theaccompanying figures and described below by way of examples of theinvention.

FIG. 1 is a block diagrammatic view of a collision warning and safetycountermeasure system for an automotive vehicle in accordance with anembodiment of the present invention.

FIG. 2 is a block diagrammatic view of a passive countermeasurecontroller internal architecture in accordance with embodiment of thepresent invention.

FIG. 3 is a flow chart illustrating a method of collision warning andactivating safety countermeasures for an automotive vehicle inaccordance with an embodiment of the present invention.

FIG. 4A is a flow chart illustrating a sensor fusion initiated passivecountermeasure method in accordance with an embodiment of the presentinvention.

FIG. 4B is a continuation of the flow chart illustrated in FIG. 4A.

FIG. 5 is a flow chart illustrating an accelerometer initiated passivecountermeasure method in accordance with an embodiment of the presentinvention.

DETAILED DESCRIPTION

While the present invention is described with respect to a method andapparatus for warning a vehicle operator of a potential collision withan object and providing countermeasures as to prevent the collision andinjury to the operator, the present invention may be adapted to be usedin various systems including: forward collision warning systems,collision avoidance systems, vehicle systems, or other systems that mayrequire collision avoidance or assessment.

In the following description, various operating parameters andcomponents are described for one constructed embodiment. These specificparameters and components are included as examples and are not meant tobe limiting.

Also, in the following description the term “performing” may includeactivating, deploying, initiating, powering, and other terms known inthe art that may describe the manner in which a passive countermeasuremay be operated.

Additionally, in the following description various countermeasures arediscussed. The countermeasures may be reversible or irreversible.Reversible countermeasures refer to countermeasures that may be reset totheir original form or used repeatedly without a significant amount offunctional deficiency, which may be determined by a system designer.Irreversible countermeasures refer to countermeasures, such as air bagsthat once deployed are not reusable. Also passive countermeasures thatare both reversible and irreversible may be used in replacement ofreversible and irreversible countermeasures.

Referring now to FIG. 1, a block diagrammatic view of a collisionwarning and safety countermeasure system 10 for an automotive vehicle 12in accordance with an embodiment of the present invention is shown. Thesystem 10 continuously monitors the environment and current situationthat the vehicle 12 is encountering through the use of a sensor fusion14. When the sensor fusion 14 detects an object in close proximity tothe vehicle 12 it generates an object status signal which is transferredto a threat assessor 16 for further evaluation. An object may be anautomotive vehicle, a pedestrian, a building, a road constructiondevice, or other object. The threat assessor 16 generates a vehiclestatus signal from continuous signal updates generated by a vehiclesensor complex 18. The complex 18 generates a vehicle sensor complexsignal, which is monitored by several system components. The threatassessor 16 generates a collision assessment signal upon generating thevehicle status signal and receiving the object status signal. An activecountermeasure controller 20 and a passive countermeasure controller 22signals active countermeasure systems 24 or passive countermeasuresystems 26 as to perform active or passive countermeasures whenappropriate in response to the collision assessment signal and thevehicle sensor complex signal, respectively. The system 10 also includesa sensor controller 28, an indicator 30, and a post collision system 32.The sensor controller 28 signals the sensor fusion 14 in response to thecollision assessment signal. The indicator 30 is used to signal andnotify a vehicle operator of a potential collision and supply otherrelated information. The post collision system 32 includes prognosticsand telematics as to inform vehicle occupants and others, such asemergency services, of vehicle and occupant statuses.

The threat assessor 16, the sensor controller 28, the activecountermeasure controller 20, and the passive countermeasure controller22 are preferably microprocessor based such as a computer having acentral processing unit, memory (RAM and/or ROM), and associated inputand output buses. The above stated assessor and controllers may be aportion of a central vehicle main control unit, an interactive vehicledynamics module, a restraints control module, a main safety controller,or a stand-alone rear collision controller.

The sensor fusion 14 may be as simple as a single motion sensor or asingle accelerometer or may be as complex as a combination of multiplemotion sensors, accelerometers, cameras, and transponders. The sensorfusion 14 may contain any of the above mentioned sensors and others suchas radar, lidar, ultrasonic, active infrared, passive infrared,telematic, or other sensors known in the art. Sensor fusion 14 is usedfor various purposes including: object detection, path prediction,environment scanning, collision assessment, and other safety purposes.The sensor fusion 14 generates a surroundings status signal, which isfurther used by the threat assessor 16 in collision probabilityestimations. The surroundings status signal may contain a camera sceneor an infrared scene of the environment surrounding the vehicle 12. Thesensor fusion 14 may determine an object relative position to thevehicle 10, an object relative velocity to the vehicle 10, and otherobject identification parameters known in the art.

The sensor controller 28 in signaling the sensor fusion 14 may beperforming several actions including: adjusting the orientation of asensor, adjusting the sensitivity or amplitude of a sensor, transmittinga signal via a transponder to a receiver located on an impending object,adjusting sensor outputs, or for performing other related actions. Bytransmitting signals to impending objects, the impending objects oroperators of the impending objects may also perform collision avoidanceand countermeasure actions.

Complex 18 is a conglomerate of various vehicle system sensorsincluding: a brake sensor, a throttle sensor, an inertial sensor, asteering sensor, a suspension sensor, a tire pressure sensor, a vehicleinertial sensor, a wheel speed sensor, a vehicle speed sensor, anoccupant position sensor, a seat belt sensor, an occupant classificationsensor, accelerometers, a pedal sensor, a seat track sensor, a steeringcolumn sensor, or other vehicle sensors. The inertial sensor may allowthe system 10 to determine roll, pitch, and yaw of the vehicle 12 or avehicle component in the x, y, and z directions. The accelerometers maybe remote accelerometers located near the outer contact surfaces of thevehicle 12 as to measure immediate collision accelerations or localaccelerometers located at various internal vehicle locations as tomeasure internal pre and post collision accelerations. The above sensorsmay be used individually, separately, or in conjunction with each other.They may also be used for multiple purposes for example in generatingthe vehicle status signal and in generating the vehicle sensor complexsignal.

The threat assessor 16 determines the potential for a collision betweenthe vehicle 12 and an object using a collision estimator 29. The threatassessor 16 gathers various data from multiple signals, such as thesensor fusion signal and the vehicle sensor complex signal inputs thesesignals into the collision estimator 29 as to assess the environment andcurrent situation that the vehicle 12 is encountering. The threatassessor 16 in response to the environment and the current situationdetermines whether any actions should be performed. The actions mayinclude signaling the active countermeasure controller 20 or the passivecountermeasure controller 22 to perform a countermeasure, signaling orindicating to the operator of the vehicle 12 of an impending potentialcollision, or may determine not to perform any action. The threatassessor 16 also predicts the future path of the vehicle 12 and of theimpending object using a path estimator 31 as to further determine thepotential of a collision.

Threat assessor 16 generates various object related information from thevarious sensors within the sensor fusion 14 and the vehicle sensorcomplex 18 including: probability that a collision may occur, time untila potential collision may occur, point of collision, impending objectprioritization, object identification, and other object relatedparameters. Point of collision refers to a spatial window where acollision may occur. All of the above information may be included in thecollision assessment signal and further used within other systemcomponents as to prevent a collision or injury.

The threat assessor 16, similar to that of the sensor controller 28, mayalso signal the sensor fusion 14 as to adjust the orientation of asensor within the sensor fusion 14, adjust the sensitivity or amplitudeof a sensor, to transmit a signal via a transponder to a receiverlocated on an impending object, or for other related purposes. Thethreat assessor 1 6 may warn an operator of an impending vehicle as wellas the operator of the impending vehicle, thereby, further increasingcollision avoidance.

Active countermeasure controller 20 includes a chassis estimator 34 andan operator intent estimator 36. The chassis estimator 34 in combinationwith the complex 18 determines the current state of the vehicle 12. Thecurrent state of the vehicle 12 may include the vehicle travelingvelocity, whether the vehicle is braking, whether the vehicle isturning, the current state of the suspension, and other vehicleconditions that are monitored by sensors. The operator intent estimator36 determines the intent of the operator including direction of travel,acceleration or deceleration intent, whether the operator is intendingto override any vehicle automated controls, and other related operatorintents and generates an operator intent estimator signal. The activecountermeasure controller 20 generates an active countermeasure signalin response to the chassis estimator signal and the operator intentestimator signal.

Active countermeasure systems 24 include brake control, throttlecontrol, steering control, suspension control, transmission control, andother chassis control systems. The active countermeasure controller 20in response to the chassis estimator signal and the operator intentestimator signal signals one or more of the active countermeasuresystems 24, as needed, so as to prevent a collision or injury. Theactive countermeasure controller 20 may autonomously operate the vehicle12 using the active countermeasure systems 24.

Passive countermeasure controller 22 contains a collision severityestimator 38 and an occupant positions estimator 40. The collisionseverity estimator 38 generates a collision severity signal in responseto the collision assessment signal and the vehicle sensor complexsignal. The occupant position estimator 40 generates an occupantposition estimator signal in response to the vehicle sensor complexsignal. The passive countermeasure controller 22 generates a passivecountermeasure signal in response to the collision severity signal andthe occupant position estimator signal.

Passive countermeasure systems 26 are signaled via the passivecountermeasure controller 22 by the passive countermeasure signal. Thepassive countermeasure systems 26 include internal air bag control,seatbelt control, knee bolster control, head restraint control, loadlimiting pedal control, load limiting steering control, pretensionercontrol, external air bag control, and pedestrian protection control.Pretensioner control may include control over pyrotechnics and seat beltpretensioners. Air bag control may include control over front, side,curtain, hood, dash, or other type air bags. Pedestrian protectioncontrol may include controlling a deployable vehicle hood, a bumpersystem, or other pedestrian protective devices.

Indicator 30 generates a collision-warning signal in response to thesurrounding status signal and the collision assessment signal, which isindicated to the vehicle operator. The indicator 30 may include a videosystem, an audio system, an LED, a light, global positioning system, aheads-up display, a headlight, a taillight, a display system, atelematic system or other indicator. The indicator 30 may supply warningsignals, collision-related information, external-warning signals toobjects or pedestrians located outside of the vehicle, or other pre andpost collision information.

Post collision system 32 may include telematics and generate postcollision signals as well as provide prognostics of vehicle and occupantstatuses. Emergency centers may be signaled such as hospitals, policestations, fire stations, or other emergency centers. The prognostics mayoffer occupant status including occupant heart rate, occupant breathinginformation, occupant positioning, or other occupant information. Thetelematics using modern verbal communication systems allows a vehicleoccupant to communicate to one of the above-mentioned emergency centers.Vehicle status information may also be communicated using thetelematics.

Although, the system signals, such as the collision assessment signaland the vehicle sensor complex signal are represented by single arrows50 and referred to as single signals these system signals may containmultiple signals from various vehicle sensors and systems.

Referring now to FIG. 2, a block diagrammatic view of the passivecountermeasure controller 22 internal architecture in accordance withembodiment of the present invention is shown. Passive countermeasurecontroller 22 contains, as stated above, the collision severityestimator 38 and the occupant position estimator 40. The passivecountermeasure controller 22 may also include a local collisionacceleration estimator 60, a countermeasure matrix generator 62, and apassive countermeasure deployment device 64.

The collision severity estimator 38 contains a timing filter 66 and aspatial filter 67. The timing filter 66 and the spatial filter 67 areused to filter false sensor data. The collision severity estimator 38monitors object time to collision and object point of collision amongother factors to determine whether received data is false data or not,so as to prevent false deployment of a passive countermeasure system 26.The collision severity estimator 38 generates a range of time having apredetermined minimum time and a predetermined maximum time in responseto the object time to impact. Collision severity estimator 38 usesaccelerometer data to confirm whether a collision has occurred. When acollision has not been confirmed within the range of time the timingfilter 66 determines that the prediction of a collision is false.Collision severity estimator 38 upon detecting that the prediction of acollision is false does not activate a passive countermeasure 26. In asimilar fashion, the collision severity estimator 38 determines whethera collision has occurred at the object point of collision using thespatial filter 67 and confirming the collision with accelerometers. Forexample, when an accelerometer located on the vehicle 12 does not detecta collision at a location on the vehicle 12 corresponding to the objectpoint of impact the collision severity estimator 38 does not activate apassive countermeasure 26. In confirming a collision a decreased amountof accelerometer data is acquired than when using only accelerometerdata to determine when a collision has occurred. The timing filter 66and the spatial filter 67 allow the passive countermeasure controller 22to determine whether to activate a passive countermeasure 26 earlier intime as compared to using only accelerometer data.

The collision severity estimator 38 contains a minimum performancestandard as to deploy a passive countermeasure system 26 in response toaccelerator data. The minimum performance standards contain thresholdlevels pertaining to sensor signals, which are overcome before deployinga passive countermeasure system 26. Collision severity estimator 38, inresponse to other vehicle sensors in the sensor fusion 14 and thecomplex 18 is capable of determining whether a passive countermeasuresystem 26 should be deployed earlier in time, later in time, or using astandard deployment time. The vehicle sensors are integrally used todetermine collision severity and allow for quicker deployment reactiontime when necessary. The collision severity estimator 38 may also adjustthe rate of deployment of the passive countermeasure systems 26.

The local collision acceleration estimator 60 generates an accelerometerbased collision severity signal. The accelerometer based collisionseverity signal is used by the collision severity estimator 38 indetermining whether the appropriate sensor signal levels are greaterthan the threshold levels, in which case the local collisionacceleration estimator 60 determines that a passive countermeasuresystem 26 should be deployed in response to the accelerometer data.

The occupant position estimator 40 monitors remote and localaccelerometers, seat belt sensors, occupant position sensors, seat tracksensors, occupant classification, and other parameters determined by thethreat assessor 16 as to best determine occupant classification,accelerations, and occupant position before, during, and after acollision. Occupant related information enables the passivecountermeasure controller 22 to deploy passive countermeasure systems 26as to best prevent injury to an occupant.

The countermeasure matrix generator 62 generates and contains a maximumsubset countermeasure matrix 70 and an available countermeasure matrix72. The maximum countermeasure matrix 70 contains maximum subsets whenthreshold levels are exceeded within one maximum subset a passivecountermeasure system 26 may be deployed. The available countermeasurematrix 72 contains all available passive countermeasure systems that thesystem 10 may implement. Incorporating a maximum subset countermeasurematrix 70 allows for quicker deployment decisions by reducing the numberof potential countermeasures that may be used from the availablecountermeasure matrix 72.

The passive countermeasure deployment device 64 in response to thecollision severity estimator 38, the occupant position estimator 40, andthe countermeasure matrix generator 62 generates the passive countermeasure signal, which includes passive countermeasure systems deploymentinformation.

Referring now to FIG. 3, a flow chart illustrating a method of collisionwarning and activating safety countermeasures for the automotive vehicle12 in accordance to an embodiment of the present invention is shown. Theautomotive vehicle 12 has, as stated above, the complex 18 thatgenerates the vehicle sensor complex signal.

In step 100, an object is detected by the sensor fusion 14 and an objectstatus signal is generated as described above.

In step 102, the vehicle status is determined in response to the vehiclesensor complex signal and the vehicle status signal is generated.

In step 104, potential for collision with the object is assessed inresponse to the object status signal and the vehicle status signal. Avehicle predicted future path signal and an object predicted future pathsignal may also be generated in response to the object status signal andthe vehicle status signal. In so doing, the future path of the vehicle12 may be compared to the future path of the object. A collisionassessment signal is generated in response to the object status signal,the vehicle status signal, the vehicle predicted future path signal, andthe object predicted future path signal.

In step 106, active countermeasures may be implemented in response tothe collision assessment signal and the vehicle sensor complex signal asneeded. The active countermeasure controller 20 transfers the activecountermeasure signal to the active countermeasure systems 24accordingly. In generating an active countermeasure signal the chassisestimator signal and the operator intent estimator signal may also beused when implementing the active countermeasures as described above.

In step 108, passive countermeasures may be implemented in response tothe collision assessment signal and the vehicle sensor complex signal asneeded. The passive countermeasure controller 22 transfers the passivecountermeasure signal to the passive countermeasure systems 26accordingly. The collision severity signal and the occupant positionestimator signal also as described above may be used when implementingthe passive countermeasures.

In step 110, a collision-warning signal is indicated to the operator inresponse to the collision assessment signal as described above.

The following methods that are described in FIGS. 4A, 4B, and 5 arepreferably performed simultaneously. Of course, in less sophisticatedsystems the following methods may be performed separately and not incombination with each other. In performing the methods simultaneouslythe vehicle 12 not only has a minimum performance criteria but also hasan additional performance criteria using information generated from thesensor fusion 14 in addition to information generated from the vehiclesensor complex 18. When the sensor fusion 14 does not detect an objectappropriately, because of the simultaneous use of the following methodsthe passive countermeasure controller 22 may continue to deploy oractivate passive countermeasures using accelerometer information alone.The ability to use only accelerometer data to activate passivecountermeasures allows the passive countermeasure controller 22 tomaintain a minimum level of injury prevention, which is equal to orbetter than the level of injury prevention of traditional countermeasuresystems.

Also, the sensor fusion 14, the sensor controller 28, the threatassessor 16, or the passive countermeasure controller 22 may determinewhether an object has been detected appropriately and generate a sensorfusion error signal when an object is not detected appropriately. Indetermining whether an object has been detected appropriately at leastone object parameter is compared with corresponding object parameterthresholds. When an object parameter threshold or group of objectparameter thresholds have been exceeded the object has not been detectedappropriately, in which case the sensor fusion error signal isgenerated. The system 10 may then perform the accelerometer initiatedpassive countermeasure method in response to the sensor fusion errorsignal instead of performing the sensor fusion initiated passivecountermeasure method.

Referring now to FIGS. 4A and 4B, a flow chart illustrating a sensorfusion initiated passive countermeasure method in accordance with anembodiment of the present invention is shown.

In step 150, a time value is monitored as to determine whether a passivecountermeasure has been performed. Also the time value allows thepassive countermeasure controller 22 to determine a duration of time,therein, when a first passive countermeasure has been performed inaddition to a current time value. Incremental times may be recorded foreach passive countermeasure, as they are activated, for furtherevaluation and assessment purposes. When the time value is not equal tothe current time value, step 152 is performed. Otherwise, step 150 isrepeated.

In step 152, the passive countermeasure controller 22 determines whethervehicle brake pressure is greater than a predetermined brake pressurevalue and generates a brake pressure signal. The brake pressure valuemay be contained within the vehicle sensor complex signal. When thevehicle brake pressure is greater than a predetermined value step 154 isperformed.

In step 154, the passive countermeasure controller activates reversibleseat belt pretensioners as to pull occupants into a seat, so as toprovide greater distance between occupants and air bags. The seat beltpretensioners are activated at appropriate levels depending on vehiclevelocities, accelerations, occupant positioning, probability ofcollision, and other related parameters.

In step 156, the passive countermeasure controller 22 determines whethervehicle yaw rate is greater than a predetermined yaw value and generatesa yaw rate signal. When the yaw rate signal is greater than apredetermined yaw rate step 158 is performed.

In step 158, as in step 154, the passive countermeasure controlleractivates reversible seat belt pretensioner.

In step 160, the passive countermeasure controller 22 determines whetherthe probability of a collision is determined to be greater than or equalto a first predetermined collision probability value. When theprobability of a collision is greater than or equal to a firstpredetermined collision probability value steps 162 and 164 areperformed incrementally or simultaneously, otherwise step 166 isperformed.

In step 162, the following is an example of object, vehicle, andoccupant parameters that are evaluated: object identificationparameters, closing velocity, time to collision, point of collision,occupant positions, occupant belted/unbelted status, occupantclassifications, brake pedal position, and steering column position.Other parameters may also be evaluated. From the evaluated parametersthe passive countermeasure controller 22 is able to further assess theprobability of a collision and the status of the vehicle 12 and theoccupants.

In step 164, as in steps 154 and 158 reversible seat belt pretensionersare enabled at appropriate levels.

In step 166, the time value is incremented and the passivecountermeasure controller 22 returns to step 150.

In step 168, upon finishing steps 162 and 164 the probability of acollision is compared to a second predetermined collision probabilityvalue, which is greater than that of the first predetermined collisionprobability value. When the probability of a collision is greater thanor equal to a second predetermined collision probability value step 170is performed.

In step 170, reversible passive countermeasures of passivecountermeasures 26 may be deployed or activated, at appropriate levels,including occupant countermeasures, knee bolsters, a load limiting brakepedal, and a load limiting steering column. Other passivecountermeasures 26 may also be deployed. Note passive countermeasures 26that are compatible with each other are the countermeasures that areactivated.

In step 172, the probability of a collision is further compared with athird predetermined collision probability value, which is greater thanthe second predetermined collision probability value. When theprobability of a collision is greater than or equal to the thirdpredetermined collision probability value step 174 is performed,otherwise the passive countermeasure controller returns to step 166.

In step 174, several values are recorded, signals from accelerometersare evaluated, and collision information is assessed. The expected timewindow of collision, the expected spatial window of collision, andcollision thresholds are stored at appropriate levels. Collisionthresholds are adjusted in response to occupant, vehicle, andobject-related information. Signals generated by remote and localaccelerometers are evaluated as to determine whether a collision hasoccurred. The passive countermeasure controller 22 also assesses thetime window of collision, the spatial window of collision, the collisionthresholds, the remote accelerometers, and the local accelerometers.Depending upon the evaluation and assessment results the passivecountermeasure controller 22 may activate irreversible passivecountermeasures, of the passive countermeasures 26, that are of coursecompatible with each other. The passive countermeasure controller 22continues to step 176.

In step 176, the passive countermeasure controller 22 determines whethera collision is confirmed. When a collision is confirmed the passivecountermeasure controller 22 continues to step 178, otherwise it revertsto step 166.

In step 178, the passive countermeasure controller 22 activates ordeploys irreversible passive countermeasures such as the occupantcountermeasures, pretensioners, air bags, air bag curtains, kneebolsters, deployable head restraints, load limiting brake pedal, loadlimiting steering column, and other irreversible countermeasures atappropriate levels. Upon finishing step 178 the passive countermeasurecontroller 22 reverts to step 166.

Referring now to FIG. 5, a flow chart illustrating an accelerometerinitiated passive countermeasure method in accordance with an embodimentof the present invention is shown.

In step 200, as in step 150 of the method of FIG. 4A a time value ismonitored. When the time value is not equal to a current time value step202 is performed, otherwise step 200 is repeated.

In step 202, the passive countermeasure controller 22 evaluates occupantand vehicle related information. Occupant positions, occupant seat beltstatus, occupant classifications, brake pedal position, steering columnposition, remote and local accelerometers are evaluated. The passivecountermeasure controller 22 also assesses collision thresholds versusremote and local accelerometer data as to determine whether a collisionhas occurred. The passive countermeasure controller 22 continues to step204.

In step 204, the passive countermeasure controller 22 determines whethera collision has occurred. When a collision has occurred step 208 isperformed otherwise step 206 is performed.

In step 206, the passive countermeasure controller 22 increments thetime value as in step 166 of FIG. 4A.

In step 208, the passive countermeasure controller 22 deploys oractivates irreversible passive countermeasures as in step 178 of FIG.4A.

The sensor fusion initiated passive countermeasure method allows thepassive countermeasure controller 22 to deploy passive countermeasures26 earlier in a collision event. By deploying the passivecountermeasures 26 earlier in time the passive countermeasures 26 may bedeployed at a reduced rate thereby potentially decreasing theprobability of injury to a vehicle occupant due to the passivecountermeasure deploying at a higher rate. The sensor fusion initiatedpassive countermeasure method also allows the passive countermeasurecontroller 22 to perform differently depending on probability of acollision occurring, which allows passive countermeasures 26 to beperformed at different collision probability levels. The increasedability to sense a potential collision and assess vehicle, occupant, andobject related information in a comprehensive and cooperative mannerdecreases the probability of an injury occurring.

The present invention provides a method for deploying passivecountermeasures in a cooperative manner as to efficiently prevent injuryto a vehicle occupant. The cooperative manner includes determiningwhether to deploy passive countermeasures at an earlier time in apotential collision event using pre-collision vehicle, occupant, andobject related information as to better assess what passive countermeasures are appropriate to deploy and to what extent.

The above-described apparatus, to one skilled in the art, is capable ofbeing adapted for various purposes and is not limited to the followingsystems: forward collision warning systems, collision avoidance systems,vehicle systems, or other systems that may require collision avoidanceor assessment. The above-described invention may also be varied withoutdeviating from the spirit and scope of the invention as contemplated bythe following claims.

What is claimed is:
 1. A method of operating passive countermeasures foran automotive vehicle having a vehicle sensor complex generating avehicle sensor complex signal, said method comprising: performing anaccelerometer initiated passive countermeasure method; performing asensor fusion initiated passive countermeasure method; detecting anobject with a sensor fusion and generating an object parameter signal;comparing said object parameter signal with an object parameterthreshold level; and terminating said sensor fusion initiated passivecountermeasure method when said object parameter signal is greater thansaid object parameter threshold level.
 2. A method as in claim 1 whereinperforming an accelerometer initiated passive countermeasure methodcomprises: evaluating the vehicle sensor complex signal and generatingan occupant evaluation signal and a vehicle evaluation signal inresponse to the vehicle sensor complex signal; assessing predeterminedcollision thresholds relative to accelerometer data contained within thevehicle sensor complex signal and generating an accelerometer assessmentsignal; determining whether a collision has occurred and generating acollision signal; and signaling passive countermeasures systems todeploy passive countermeasures in response to said occupant evaluationsignal, vehicle evaluation signal, said accelerometer assessment signal,and said collision signal.
 3. A method as in claim 2 wherein evaluatingthe vehicle sensor complex signal comprises evaluating at least one ofoccupant position data, occupant belted data, occupant classificationdata, occupant acceleration data, and seat positioning data.
 4. A methodas in claim 2 wherein evaluating the vehicle sensor complex signalcomprises evaluating at least one of a brake signal, a throttle signal,a steering signal, a suspension signal, a tire pressure signal, avehicle inertial signal, a wheel speed signal, a vehicle speed signal,an occupant position signal, a collision signal, a seat belt signal, anoccupant classification signal, a pedal signal, and a steering columnsignal.
 5. A method as in claim 2 wherein assessing predeterminedcollision thresholds relative to accelerometer data comprises comparingpredetermined collision thresholds to remote collision accelerometers orlocal accelerometers.
 6. A method as in claim 2 wherein signalingpassive countermeasures systems to deploy passive countermeasurescomprises deploying at least one of a occupant countermeasure,pyrotechnic pretensioner, an airbag, an airbag curtain, a knee bolster,a deployable head restraint, a load limiting brake pedal, a loadlimiting steering column.
 7. A system as in claim 6 wherein signalingpassive countermeasures systems to deploy passive countermeasurescomprises deploying reversible or irreversible passive countermeasures.8. A system as in claim 6 wherein deploying passive countermeasurescomprises deploying passive countermeasures at appropriate determinedlevels in response to said occupant evaluation signal, vehicleevaluation signal, and said accelerometer assessment signal.
 9. A methodas in claim 1 further comprising monitoring an amount of iterations saidmethod has been performed.
 10. A method as in claim 1 wherein performinga sensor fusion initiated passive countermeasure method comprises:determining whether vehicle brake pressure is greater than apredetermined brake pressure value and generating a brake pressuresignal; and deploying passive countermeasures in response to said brakepressure signal.
 11. A method as in claim 1 wherein performing a sensorfusion initiated passive countermeasure method comprises: determiningwhether vehicle yaw rate is greater than a predetermined yaw value andgenerating a yaw rate signal; and deploying passive countermeasures inresponse to said yaw rate signal.
 12. A method as in claim 1 whereinperforming a sensor fusion initiated passive countermeasure methodcomprises: sensing an object via the sensor fusion; determiningprobability of a collision between the vehicle and said object;evaluating object related information and generating an objectevaluation signal; evaluating the vehicle sensor complex signal andgenerating an occupant evaluation signal and a vehicle evaluation signalin response to the vehicle sensor complex signal; signaling passivecountermeasures systems to deploy passive countermeasures in response tosaid object evaluation signal, said occupant evaluation signal, and saidvehicle evaluation signal.
 13. A system as in claim 12 signaling passivecountermeasures systems to deploy passive countermeasures comprisesdeploying reversible or irreversible passive countermeasures.
 14. Amethod as in claim 12 further comprising: assessing collision thresholdsrelative to accelerometer data contained within the vehicle sensorcomplex signal and generating an accelerometer assessment signal; andsignaling passive countermeasures systems to deploy passivecountermeasures in response to said accelerometer assessment signal. 15.A method as in claim 12 further comprising: determining whether acollision has occurred and generating a collision signal; and signalingpassive countermeasures systems to deploy passive countermeasures inresponse to said collision signal.
 16. A method as in claim 12 whereinevaluating object related information, evaluating occupant relatedinformation, evaluating vehicle related information, signaling passivecountermeasures systems is performed when said probability of acollision is greater than or equal to a predetermined collisionprobability value.
 17. A method as in claim 12 further comprising:determining said probability of a collision is greater than or equal toa first predetermined collision probability value; and deploying areversible passive countermeasure.
 18. A method as in claim 17 furthercomprising: determining said probability of a collision is greater thanor equal to a second predetermined collision probability value; anddeploying an additional reversible passive countermeasure.
 19. A methodas in claim 18 further comprising: determining said probability of acollision is greater than or equal to a third predetermined collisionprobability value; and deploying an irreversible passive countermeasure.20. A method as in claim 19 further comprising: determining saidprobability of a collision is equal to a fourth predetermined collisionprobability value; and deploying an additional irreversible passivecountermeasure.
 21. A method of performing passive countermeasures foran automotive vehicle having a vehicle sensor complex generating avehicle sensor complex signal, said method comprising: evaluating thevehicle sensor complex signal and generating an occupant evaluationsignal and a vehicle evaluation signal in response to the vehicle sensorcomplex signal; assessing collision thresholds relative to accelerometerdata contained within the vehicle sensor complex signal and generatingan accelerometer assessment signal; determining whether a collision hasoccurred and generating a collision signal; and signaling passivecountermeasures systems to deploy passive countermeasures in response tosaid occupant evaluation signal, vehicle evaluation signal, saidaccelerometer assessment signal, and said collision signal.
 22. A methodof performing passive countermeasures for an automotive vehicle having avehicle sensor complex generating a vehicle sensor complex signal, saidmethod comprising: determining whether vehicle brake pressure is greaterthan a predetermined brake pressure value and generating a brakepressure signal; determining whether vehicle yaw rate is greater than apredetermined yaw value and generating yaw rate signal; sensing anobject via the sensor fusion; determining probability of a collisionbetween the vehicle and said object; evaluating object relatedinformation and generating an object evaluation signal; evaluating thevehicle sensor complex signal and generating an occupant evaluationsignal and a vehicle evaluation signal in response to the vehicle sensorcomplex signal; assessing collision thresholds relative to accelerometerdata contained within the vehicle sensor complex signal and generatingan accelerometer assessment signal; determining whether a collision hasoccurred and generating a collision signal; and signaling passivecountermeasures systems to deploy passive countermeasures in response tobrake pressure signal, yaw rate signal, said object evaluation signal,said occupant evaluation signal, and said vehicle evaluation signal,said accelerometer assessment signal, and said collision signal.